Trailer draft connection



Sept.l 14,v 1943. D, 0 AREHART 2,329,380

TRAILER DRAFT CONNECTION Filed March 24, 1941 4 Sheets-Sheet 1 INENTOR BY I DAVID 0..'EHRT ATTORNEYS Sept. 14, 1943. D. D. AREHART TRAILER DRAFT CONNECTION 4 sheets-sheet 2 Filed March 24, 1941 INVENTOR BY DAVID D.AREHRT A TIORNE YS D. D. AR'EHART TRAILER DRAFT CONNECTION Filed March 24, 1941 4 sheets-sheet s FIGJI.

INVENTOR DAVID D AREHRT BY f TTORNE YS sept. 14, 1943.

llll illlllllflll FIGJO.

Sept. 14, 1943. I D. D. AREHART 2,329,380

TRAILER DRAFT CONNECTION Filed March 24, 1941 4 Sheets-Sheet 4 if# 2O i0 INVENTOR DAVlD DAREHART www /MM HSM TTORNE YS Patented Sept.y 14, 1943 I' rRarLEnDRAFT ooNNEC'rIoN y p David D. Arehart, Flint, Mich.;'assignortoflalace n y 'Travel Coach OorporatonFl int, Mich., a-,c`or n' New @www y ApplicationlMarchZL, 1941,1Serial "Nor 384,987 a a f Y f1.' L s claims 1(01, 280453349 l 'The' invention relates A- to trailer" draftV co'nec# 'Fig.`-10`i'sfa View' in sectionon-a line correspondtions such, for instance, as are used in connectingingtvo line A'IIJ-' -III of Fig.-8; and l v trailer cars to automobiles. I v -f Figrllis'a view in sectionon a line correspond-y It is the primary object oaf-thefi'nventiori) to ing'to lineVII-n-II of Fig.f8. avoidy the oscillations iwhichusually occur with Referring to Figs.` `1 and r2, the numeral kIIJ such draft connections in bothA verticalv vand horidesignates the longitudinal'frame' members of the zontal planes. n j g v towing vehicle, and II thelcorres'ponding ,frame It 'is a further object 'tor vrnaintainay substan-l membersof the trailer. The body I2 of the trailtially rigid connection between the` framesr ofthe e erisfunbalanced on the wheelsv I3, so that a contractor and trailer vehicles travelingl over ia/level` 10 sderable'portion' of the' weight'is supported by road' bed and a substantially straight line; f the towing vehicle orfv car. 'The lifting device or while at the same time'vpermitting relative 'angujacky I4- (shown in vdash 'a.nd dot. lines) is used lar movement `between these frames when'necesg onlygtdr'aise or lowerv the front end of the frame sary, as in turning or'changein slope of the 5I to facilitate coupling orvuncoupling with the road, e' f -f15 towing Jcarfandtolprovidefasupporting wheel A vsull further object is to rattain` better disforthe lfrom lend ofthe trailer when the towing tribution of the load upon the supporting wheels. car isv detached. It is drawn up clear of the particularly withtrailers or the'type where a por# ground or is removed entirely-when the trailer is` tionlof the load' is normallyj carried "by the connected as shown. a Y f tractor. .j I Q 20" Itisobvious'thatifthe frames I0 and II were With these objects in view', the invention y"con-j rigidlyA connected to each other to form virtually f sists: y 1 one "solid trame; the weightof the forward parti.; First, inthe constructionof a trailerdraft con-` A of the combination a would'.A be proportionately ne'ctionfwhich is'adapted forl rigid :vittachrr-1entV borne byboth the rear'wh'eels I5 and the front to both the tractor and trailer frames; A '25 wheels Ily of ythe-towi'ngvcar, provided that' all of Second, in'a'construction which',fwhile.permit* the whee1s,inc1udin'g those of the trailer,v were ting relativeangular movement betweenthememu on alevelsurfacefla-t'alltimesf' However, since bers thereof under' predetermined stresses, isnor-l it is necessarytofhave joints in 'the Coupling t0 mally held suiiciently; rigid to resist oscillations; permit the frames II)A and II to change angularity and i 'l v j 30 in relationt'oeach other'to compensate for travel Third,`in various features of more specific con over uneven ground and to` permit turning to struction as hereinafter set forth. y changeidirection of traveljan absolute rigid con- In the drawingsz' 's f' j h nection',foffcourse, cannotbe'maintained. With Fig. 1 isa plan view, partially' ,cliagramrnaticgjy 'of g a free joint'inA the coupling, the frame' I0 becomes a trailer and towing vehicle chassis connected 35 a lever'fulcrumed either on the car rear. wheels by a coupling nea'ns embodying features or this Iiil or'yfrontY wheels' I6. In either case, :by` far the invention;A I y greater portion-of the load is borne bythe rear Fig.2 isa view thereof inside elevation; y wheels I5.- Olne Object 0f thfi Coupling shown Fig. 3 is an enlarged view taken on aline corvy herein is to provide Ta. yielding resistance to the f responding to line 3+3jof Fig.v l, showing details' ione/Xing or yhinging` action, which .will maintain of the coupler;

rigidity sufficient to support vthe normal loadonY Figg4isaplanviewof Fig. 3; y l the coupling, lbut'.. which willyiel'diand permit Fig. 5 is ka View in section vony a line correspond` hinging action Vwhen travel over irregular surfaceV e `ingto line5-5of1i1'g-3;vr V u Fig. `6 is a view in section on a line corresponde" 45 larityvv relative to each other. A f e ing t0-1ines .`0fFig3; l' f Inthespecicconstruction shown "herein, a Fig. '7 isa view, partially insection, onfa line Sllb-flllv 20 is Securedjto` a Cross member y2| corresponding to line 1 1 ofFig;` 4, illustrating and side'rails of the .frame I0`of the towing car compels the framesu I0 and II` to change `angumeans of attachingthe coupler 'at diierent and is also partially supportedbythebumper;

heights on the trailer;- f A l Fig. 8 is e view similar to Fig. 3` (in section sub-.framerbearisid extension ofthe .frame on a line corresponding to'line 8--8 ofFig; 9), I0'. The-sube'f'rame 20 carries a. 111g .2.3 `WIT-mh 50r bar 22 asillustrated, it being .-importanttliatV the' showing a modification in the construction and serveslas. a bearing block to support the weight e,

operational.' certain parts; l l c Fig;9islap'1anview oilig;` S Y 65 bearing to permltturningi-l 1 of thefront part ofthe trailer, and las-aA kingbolt l The coupling member shown in the drawings comprises a bracket 25 which is secured to the forward end of ,the trailer frame II, preferably as close to the lifting jack I4 as good construction will permit. (See Figs. 3 and 4.) In Vthe structure shown, plates 26 which are secured to the sides of the frame I I, are tied together by a plate 21. A series of holes 28 in the plates `2li and 21 for the bolts 2,9 provide means of attaching the bracket 25 at different heights to le'vel the coupler with the lug 23. (See Fig. '1.)` y f A yoke 39 is connected to the bracket by av stud 3I which is rotatable in f jbearing `325.; and is held in assembly by a thrustnut 33.'. Turning of the stud 3l permits thi-yoke 30 tov turn in15 a transverse vertical plane relativeto'the trailer frame II, topermit the trailer to lean sidewise relative to the towing vehicle, toallow 'for travelover uneven roadway. If resistance to freeuturn-k-` Y ing action of the stud 3| is desired to check pos# 2g sible tendency to periodic rolling actionhbrake discs 34 may be interposedrbetween th e yoke 30 and a thrust disc135, thedegree of pressurebeing ladjusted to suit by the nut 3 3 Obviously, this is only one of several means of yieldinglyopposing free turningof the stud3I; l Y; l,

,The yoke SII-has al pair of forwardly extending arms 36 terminating in bearings 31A in which is rotatably mounted va hinge pin 3.8,. The pin, 38 carries axbell cranklever 39 to which itisyheld in assembly by Va lock `pin 4I). A downwardly-` elitending kingbolt 4I of the lever 3 I'Iisrotatablyjr iitted to the lug 23 onthetowng car,fra m e ex-` tension, the weight being bornebyI a thrust collar 42. The kingbolt may be lprevented.from acci-l dentally jumping outAof engagement with the lug 23, by the pin 43 as shown, or by--any othersuitable locking meansi.; ,Y y; 1

In the construction shown in detail jin :Figsy 3, 4 and 5, a rearwardly.lextendinsarm 4,5 Laf the bell crank lever 39 has a. surface o its loy er; side whichis appropriately,,formedr tojrigage@ i thrust bar 46 s which",iscarried yon the lower ends ,of` a pair ofpull rods41. .The rods/41 arey slidablymounted in bearing bosses43 o n the yoke 1 p 30 vand yieldingly hold the ibarN-Ilvagainst the lower sideof the armi45 fbyme'ans-,of compres7 sion springs49 and adjustng-,nuts,150

Since the mounting `Qfpth kngbpll Mlm.. the lug 23 prevents anyturningzof theleverr39` inza yvertical plane relative to the towing fr car,A frame I0, the connectedends o f the-trames ,0; and II cannot sag and, impose-excessive loadeny the rear wheels vI of ,the towing `car; ,.withciutr compressing the springs49.` The nuts gmayb adjusted to give the springs 4,9 sufficient lstiffness to hold the lever arm 451mm beingturned Vby the normal load on the hingerpin 3 8, but to yield when contour of the roadway compels the armA to swing downwardly.: Since the arm ,is free to ,0 move upwardly away .ifromithe thrustibar 4 there is no resistance, in additiongto, normal load, to flexing action between the ,frames III andf II whenithe wheels I5 are compelled to rise above the plane of the wheelsnlliand/ I` By adjust;- ing the springtensiontosustain more thang the normal load,` an archedfeffectof the connected` vehicle frames may be obtained @to `transfer a,r still greater portion; of ythe lloadI toV the@ front e wheels of the towingfcar. ''ffflgi 11 "gp70 To obviate side-swaying lof the `front end;of the trailer and rear endlof thextowing car, it is desirable to provideresi'stance to .free turning of the kngbolt 4I inthe' 1ug23.1/One means.. oi accomplishing this result comprisesiaca1n5lz being. appropriately" formed' tlsrvefas :retainers bushings 16 in thebar 13 projet upwardly ia rotatably mounted onthe bolt 4I and having a notch 52 appropriately formed to engage a key 53 which is secured to the lug 23 (see Fig. 6). It is apparent that any movement of the trailer or towing vehicle out of alignment with each other in a'horizontal planemust turn the cam 5I on the bolt 4I. The cam 5I has flat faces 54 on opposite sides which are engaged by flat or leaf springs 155 :which are anchored tothe arm 45 and bear against the cani. ARotation of the cam must swing the springs 55 outwardly, as shown "'by'dash and dot lines in Fig. 6. The springs are` designedjwith suiiicient stiiness to resist sidesway of the trailer, but to yield when the towing vehicle is turned to change direction of travel as desiredf 'Iheam is preferably so shaped that it meets the greatest resistance to turning when thetwovehicle.. frames are approximately in alignment f or travel straight ahead, there being Yonly frictional resistance to continued turning afterthe frames I0 and II have beenswung considerably out oi alignment with each other and ythe springs 55 arein contact with curvedsur. faces onthe cam 5I. 1

I n thegconstructionjshown 'in f Fig's.' 3, 41 the springsf 4 9 provide resistance ,to downward. iiexing of the couplingK and serve to distributefaf' greaterportionof the trailer vweight tothe front wheels o fgthe,car. There ,noresistar'i'ce to"up, ward, flexi n g except thefweight on the lhinge sa. .This amantes' simsen@ fo overcame mi" tendencyfof itheffrontend of the trailer'to litf, up4 whileim-irration.l 1Vif .thatiailer' w1 1eels`. arefl located so `t'hat a 'onsidrable 'portion o'f` th` trailer weight is yborneby the towing car. Hw',, ever, if little ornqne of; the trailer weight'is boriirybyfy the. ,t owi`1ig car,' tlfi`e front end fof; trauer wml tea-d, t wingyripwafdiy, while; iii'. motion :meurt theajrmsoir the' barter?, Conditin WldJeXs't if tflellocatn Of tra l wheels andadistribution of trailer load were no in proper relationto give' correct balance.

for the upprendspf (tliespiingsl The springs 59 are mounted ristuds.69l Y are threaded or otherwise securedbossesl',`I-Dr onthe yoke 3Q, the upper ends fof 'he studscary ing retainers 1I and adjusting 2 The lower ends of the springs ifbeara'gamsgathrus u 69. andcarries athrust screw 114; which A engages a bearing Surface. 15.01;, the upper. side. aime. .1 45.` In r.the form of constructiorishown enough@ Serve as ,spring lretarltr,*artid-als.1,115`V creanme-.length of guidebsarina f..

When both 0f ,thel thrustbalsr".

.. vmili in Contact with the yoke or .framermambexs c asaaeo contact with the arm 45, the latter cannot oscillatein either direction without. compressing one painof the springs. By means of-f'the `thrust,

screwsthe arm 45 may be adjusted toany posif tionbetween thebars 63 and 13 andconsequently f determine the angular relationy between ythe trailer vframe Il and the `towing -car framey I0.

ythe front wheels. This effect depends upon the springs V58 having sufficient resistance to support' the lnormal load on the thrust jbar 63 and thus maintain rigidity up tothe desired yielding point.;

,' Ihe vsprings 59.- oppose any tendency uof .the

front end of the trailer to oscillate vupwardly when too small a portion of the weight is borne bythe towing car. By adjusting the arm 45,130 a, positionbelow the position for parallel alignment ofthe frames IB and Il, Vweight on ,the front wheels'ofnthe towing car is reduced, which tends to shiftmore of the carweight to itsrear wheels and thus oppose upward oscillation ofthe front end ofthe trailer. kThe Vnuts 66 and 12'may be adjustedrto ygive different degrees of resistance to the two.. pairs of springs 58 and 59, or` springs of ydiierentjrates of capacity may be used, as desired, to meet different conditions of weight distribution.

With this means of controlling resistance to flexing of the coupling, both downwardly and upwardly, the wheels of the trailer can be placed farther forward than would otherwise be permissible, thereby placing substantially all of the trailer weight directly on the trailer wheels without causing the trailer to sway. The means of adjusting each pair of springs independently of the other pair is a decided advantage especially in the use of cargo trailers or any other trailer in which the center of gravity location may be changed at different times.

It is obvious that the objects set forth in this specification could be accomplished with various changes in details of construction. Therefore, it

- is to be understood that this invention is not to be limited to any specific form or arrangement of parts.

What I claim as my invention ist l. A trailer draft connection comprising members adapted for rigid connection respectively to 3. ,A" trailer draft connectioncomp'rising mem bers adapted for rigid connection; respectively with ythe-:frames ofrtheltracto'r and trailer ve hiclesr a; "membern vertically vadjustably secured to one.n of said members toA be '.held fin rigid rela. tionbthereto,i.-a Aswivel (sonnet/"tion with said last 1: mentioned?.y member; for ,relative rotationeinf. a transverseutplane :and a ,fpivotal connection :with

the;` other'` of!y .said yfirst mentioned .membersfor; 'n relativelangular movement fin' longitudinal, .vereJ s ticaljand; horizontaljplanes', means .for holding, said pivotally.connectedmembersfin rigid align?.- ment ina' vertjcaleplane resiliently yieldable un-K4 der a predetermined stress, and means for resil-` t ientlygalnd, frictionally'f resisting yrelative',angular. movement. ofi said pivotally @connected members; inza'horizontalplane.; v: :i r

h4.-,A trailerldraftlconnection:comprising a sub.

. framef-attac'hablef tothe. v frame of 'atractorflve- ,Y

the frames of the tractor and trailer vehicles,

a pivotal connection between the members for permitting relative angular movement thereof in tion to each other in each of said planes yieldable under a predetermined stress and operable in each of said planes in all positions of adjustment of said members in the other of said planes.

2. A trailer draft connection comprisingmembers adapted for rigid connection respectively to the frames of the tractor and trailer vehicles, a pivotal connection between said members for permitting relative angular movement in both vertical and horizontal planes, and means for normally holding said members in vrigid alignment when said tractor is traveling in a straight line, said means being yieldable upon change in direction of movement of the tractor and also upon change of angle in the road bed remaining operable in each of 'said vertical and horizontal planes in all positions of angular adjustment of said members in the other 0f said vertical and horizontal planes. f

khicletobe;rigid therewithand to extend in rear thereof having also a yhooked connection.with. the bumperA for. furtherisupport, a member adapted forrigid,connection with the yframe. ofv the trailer.',tbirextendforward thereof, a member :hav: i ing-alhorzontal.pivotconnecting rit to the forward4 end portion 'ofthe last Vmentioned member. and overlapping the rear end of said sub-frama'iva ylringfpin'.;con;`necting said overlapping portions, r resilient means for resisting relative angular movementof said members connected by the horizontal pivot yieldable under a predetermined stress, and resilient means for resisting relative turning movement of the members connected by said king-pin also yieldable `under a predetermined stress.

5. A trailer draft connection comprising a subframe rigidly attachable to the frame of the tractor vehicle to` extend centrally in rear thereof, the latter portion being provided with a, hook for engagement with the rear bumper of the tractor to afford further support, a king-pin engaging said central rear portion, a member mounted on said king-pinv to extend rearwardly therefrom, a member adapted for rigid connection with the frame of the trailer to extend for ward therefrom, a member `having a swivel connection with saidy forwardly extending portion and also provided with a forwardly extending bifurcated portion for embracing the `member mounted on said king-pin, a horizontal pivot connecting the latter member with said bifurcated portion adjacent to said king-pin, a U-shaped yoke having parallel-portions slidably engaging bearings in the furcations of said bifurcated member to extend upward beyond the same andk with a connecting portionextending beneath the rear end of said member connected to the kingpin, springs on the upwardly extending parallel portions for yieldably resisting downward movement thereof, an eccentric cam on said king-pin, and resilient arms connected to the rear portion of the member pivoted on said king-pin, said arms extending forward to embrace said eccentric cam and to resiliently and frctionally resist rotation of said last mentioned member on said king-pin, whereby oscillation of said draft connection is resisted in both horizontaland vertical planes. f

6. A trailer draft connection comprising members adapted yfor rigid connection respectively to the frames of the tractor and trailer vehicles, a king-pin secured to and projecting upward from the tractor member, a member pivoted on n said king-pin projecting rearward and slightly downward therefrom, a bifurcated member sewardly extending member, said cam being held from rotation on said king-pin, a pair of spring arms securedto said rearwardly extending member and projecting forward on opposite sides of Y said cam to frictionally engage the same, said cam being so fashioned as to spread said spring armsy upon "a pivotal movement` of said rearwardly extending member-on said king-pin and thereby resisting oscillations of saidmember on said king-pin.4

7, A trailer draft connection comprising members adapted for rigid 'connectionrespectively to the frames ofthe tractor and trailer vehicles, a

king-pin secured to and projecting upward from the tractor member, a member pivoted on said king-pin projecting rearward and slightly downward therefrom, a bifurcated member secured to said trailer member embracing the member pivoted on saidking-pin and connected thereto by a horizontally extending pivot, a U-shaped member slidably secured in inclined bearings on said bifurca-ted member and engaging the under sidey of the rear end of said rearwardly extending member, springs for yieldably resisting downward movement of said U-,shaped member and therebyresisting yupward swinging movement of said bifurcatedmember about said horizontal pivot.

Y8. A trailer draftlconnection comprising members adapted for rigid connection respectively to the frames of the tractor and trailer vehicles, a'king-pin secured to and projecting upward from the tractor member, a. member pivoted onsaid king-pin projecting rearward therefrom, a bifurcated member secured to said trailer member embracing the member pivoted on said king-pin and connected kthereto by a horizontally extending` pivot, a pair of yokes respectively above and below said rearwardly extending member and slidable in bearings arranged at different anglesvin the furcations of said member, and springs for resiliently resisting movement of said yokes in said bearings whereby relative movement of said tractor and trailer members in a vertical plane is resisted in each direction by said springs.

DAVIDV D. AREHART. 

